Mobile phone-assisted basic life support augmented with a metronome

Background: Basic life support (BLS) performed by lay rescuers is poor. We developed software for mobile phones augmented with a metronome to improve BLS.

Study objectives: To assess BLS in lay rescuers with or without software assistance.

Methods: Medically untrained volunteers were randomized to run through a cardiac arrest scenario with ("assisted BLS") or without ("non-assisted BLS") the aid of a BLS software program installed on a mobile phone.

Results: Sixty-four lay rescuers were enrolled in the "assisted BLS" and 77 in the "non-assisted BLS" group. The "assisted BLS" when compared to the "non-assisted BLS" group, achieved a higher overall score (19.2 ± 7.5 vs. 12.9 ± 5.7 credits; p < 0.001). Moreover, the "assisted BLS" when compared to the "non-assisted" group checked (64% vs. 27%) and protected themselves more often from environmental risks (70% vs. 39%); this group also called more often for help (56% vs. 27%), opened the upper airway (78% vs. 16%), and had more correct chest compressions rates (44% ± 38% vs. 14% ± 28%; all p < 0.001). However, the "assisted BLS" when compared to the "non-assisted BLS" group, was slower in calling the dispatch center (113.6 ± 86.4 vs. 54.1 ± 45.1 s; p < 0.001) and starting chest compressions (165.3 ± 93.3 vs. 87.1 ± 53.2 s; p < 0.001).

Conclusions: "Assisted BLS" augmented by a metronome resulted in a higher overall score and a better chest compression rate when compared to "non-assisted BLS." However, in the "assisted BLS" group, time to call the dispatch center and to start chest compressions was longer. In both groups, lay persons did not ventilate satisfactorily during this cardiac arrest scenario.